Multispectral Remote Sensing Study of
Industrial Discharges
CHESTER T. WEZERNAK, Assistant Professor
School of Public Health
F. C. POLCYN, Research Engineer
Infrared and Optics Laboratory
University of Michigan
Ann Arbor, Michigan
INTRODUCTION
In view of the scope, dynamic nature, and dimensions of the water pollutuion
control problem, additional techniques are needed to supplement existing methods
of pollution surveillance and data acquisition. This is particularly true for the Great
Lakes, coastal areas, large river systems; and difficult to reach locations. As a consequence, interest is growing in the concept of remote sensing.
The term remote sensing refers to the acquisition of information about objects
or phenomena in our environment through the use of sensory devices at positions
away from the subject under investigation. In this investigation the term is restricted
to the use of an airborne system and measurement of interactions in the ultraviolet,
visible, and infrared regions of the electromagnetic spectrum.
The amount of information potentially obtainable from remote measurement
of electronmagnetic energy is quite large. As Colwell, et. al, (1) have emphasized,
only four interactions are possible when a photon of any specific energy strikes a
substance. The energy may be absorbed, emitted, scattered, or reflected. Therefore,
in principle information can be obtained regarding an object provided of course that
the instrumentation used is capable of defining spectral properties in sufficient detail.
OBJECTIVES
The data acquisition needs in the water pollution control field include information regarding the following: 1) materials on the surface of the water; 2) materials
suspended in the water, and 3) materials dissolved in the water. Some of this information is at times expressed in broad term parameters such as suspended solids, total
carbon, oils, etc.; and also of course in very specific chemical terms. Additionally
there is a need for information of a strictly physical nature; such as temperature or
data regarding pollution dispersion patterns. The information needs are clearly quite
extensive and as a result cannot be fully realized with a single sensor system.
The present study deals with one sensor system and is directedat the examination of industrial effluents. The objectives were: 1) to evaluate the ability to detect
effluent discharges, 2) to develop spectral response curves for each effluent, and 3) to
define the distribution patterns of selected discharges.
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